They found that an increase in body fat of 5 kilograms (11 kilograms) was associated with a 35% increased risk of this type of breast cancer. A 5-kg increase in the fat mass of the trunk was associated with a 56% increase in risk.
Magnesium fat is "determined by the fats contained in the body, with the exception of the head and limbs", according to the study.
"The main incentive is that excessive body fat, even if you have normal body weight, is associated with an increased risk of breast cancer," said Dannenberg.
BMI of a person is calculated according to a formula that includes their height and weight; according to the study, "normal" BMI is between 18.5 and 24.9.
The researchers also studied blood data that were intended for other factors known to be involved in the development of breast cancer, such as raising insulin molecules, at the beginning of the Women's Health Initiative.
The authors of the editorial board also point out that other researchers looked at the different results with the issue and warned that "these findings indicate that the components of metabolic health and not the presence of a complete metabolic syndrome can contribute to the risk of breast cancer."
"I think this is a good step forward, which leads us to look at the ITM index as an indicator of obesity, which really looks at a particular site of fat concentration in the body," said Anton-Culver, who did not participate in the study.
Scientists knew that there was a link between obesity and cancer, but Anton-Culver says that a new study moves research beyond this general association.
"They say in the summary correctly that obesity is associated with breast cancer, and more precisely, obesity around the abdomen is more specific to this association," she said.
Although Anton-Culver thinks that the study is strong, she pointed out that she found only a certain cancer.
"I do not know if we look at the same problems with other types of cancer, because it's the result, what will it be, or is it specific to breast cancer?" she said. "We need to ask the next question because obesity is a risk factor for other types of cancer."